1. Field of the Invention
The present invention is in the field of systems for tracking the movement of objects, and, more particularly, is in the field of tracking a plurality of animals during a race.
2. Description of the Related Art
A solution to track race horses at racetracks has been sought for years. The conventional method of tracking horses is to utilize one or more individuals called “chart callers” who visually track the race horses with binoculars during the race and translate the relative positions and speeds of each race horse to a “chart.” This procedure is neither precise nor continuous. Furthermore, the procedure is not 100% repeatable since human error can be introduced.
Various radio frequency (RF) tracking systems have been proposed to improve the current chart calling method. Such systems include, for example, RF identification (RFID), angle of arrival (AOA) systems, time difference of arrival (TDOA) systems, and the like. Such systems are expensive to acquire and operate, require significant modifications to the infrastructures of racetracks, and are complex to maintain and operate. Accordingly, such systems have only been used sporadically and have not achieved widespread acceptance and use. Video-based tracking solutions have also been sought but have been similarly dismissed due to difficulty in ensuring a positive track continuity and track-to-track associations due to tracking issues in foggy conditions and other poor weather conditions. Since horse racing must operate in all weather conditions, the video-based tracking solution, even if used as an aiding device, is not a preferred method for the horse racing industry.
Several new global positioning system (GPS) based solutions (both code phase and carrier phase tracking types) have been proposed and tested in recent years, but the proposed systems have not been used for live racing due to several technical problems, including, for example, difficulty in acquiring and tracking GPS signals in front of buildings and near the grandstand, trees, light structures, fences, and other objects that can block the signal reception at a number of locations along the track. Other technical problems with proposed GPS-based systems included large multipath errors in the starting gate, which caused a loss of reception and required long reacquisition times to regain an accurate tracking solution. The loss of reception caused the loss of lock within the starting gate, thus making the system ineffective as a start timing system and as a system for determining the positions of the racehorses at various points along the racetrack. In addition, the proposed units for mounting on horses were large and heavy and had high battery usage. Accordingly, GPS-based systems are not being used at racetracks.
After more than 10 years of trying to find an accurate and continuous tracking solution with GPS-based systems, RF-based systems, and/or video-based systems, racetracks in the United States and other North American countries still have not implemented a system that meets all requirements for replacing the conventional chart caller system.